1. Field of the Invention
The present disclosure generally relates to corrosion control. More particularly, the disclosure pertains to the use of niobate compounds to reduce or inhibit corrosion of surfaces in aqueous systems.
2. Description of the Related Art
Chromate, molybdate, and other anions with metals in a high oxidation state can be effective as corrosion inhibitors in aqueous systems. However, chromates have essentially been banned from use around the world due to their elevated toxicity levels. Molybdates have generally replaced chromates since they have lower toxicity levels. However, molybdates are much more costly than chromates.
Other oxyanions, such as tungstate and vanadate are also known to be effective corrosion inhibitors but they are even more expensive than molybdate. Nitrites have also been used to control corrosion but in general, when used alone, high doses of nitrites must be applied for an effective treatment. Nitrites can also serve as a source of nutrients for microorganisms in aqueous systems. As such, a more cost effective corrosion inhibitor is needed that does not have the negative issues associated with prior art corrosion inhibitors.